I was just going through old visa bills. I throw them out after 6 years to make room in the folder. You see my contractual liability expires after 6 years and I won’t need them in court in the event of a disputed bill. Full disclosure: early training as a lawyer can lead to filing difficulties in later life. I see that I paid €19.53 on 16 February 2007 to become a lifetime member of Library Thing. Money well spent, I think.